Construction of malt and grain mills



(No Model.) 2 She-ts-Sheet 1.

0.'J. HEXAMBR. GONSTRU@TIONv 0F MALT AND GRAIN MILLS. No. 292,488. IPatented Jan 29; 1884. k k

WlTNESSESg I Q Q INVENTOR v Wmw,

(No Model.) 7 .2 Sheet s -shee fifi C. J. HEXA'MER. CONSTRUCTION OF.MALT AND GRAI IMILLS. No. 292,488. Patented Jan. 29, 1884. 1

WITNESSES:

INVENTOR u. mas. mmmm w m E UNITED STATES IATEN-r Erica.

CHARLES JOHN HEXAMER, or PHILADELPHIA, PENNSYLVANIA.

CONSTRUCTION OF MALT ANDGRAIN MILLS.

SPECIFICATION forming part of Letters Patent No. 292,488, dated January29, 1884.

Application filed February 27, 1883. (No mode-1.1 d

To all whom, it may concern.-

Be it known that I, CHARLES JOHN HEX- AMER, a citizen of the UnitedStates, residing at the city and county of Philadelphia, and State ofPennsylvania, have invented certain new and useful Improvements in theConstruction of Malt and Grain Mills, of which the following is a full,clear, and exact description, reference being had to the accompanyingdrawings.

Figure 1, Sheet 1, is a transverse vertical section of a malt-mill'orother grain crushing or grinding mill provided with my improvements, asthey appear previous to the occurrence of a clustexplosionwithin themillbox. Fig. 2 is a like sectional view, showing. the position of theparts immediately after such an explosion. Fig. 3, Sheet 1, is a section on the line a b, Fig. 1, showing the construction and arrangementof the drop-gate. Fig. 4, Sheet 1, is a detail of wedge or key and itsconnections for holding the rope or rod which sustains the drop-lever.Fig. 5, Sheet 1, is a detail of said rope and fusible couplings. 1

Like letters of reference, where they occur in the several figures,indicate like parts.

The object of this invention is to prevent those hitherto disastrousfires occasioned by explosions of the fine dust arising from grinding orcrushing malt or grain, induced by the mill rolls striking some foreignhard body such as a stone or piece of iron-and thereby producingsparkswhich ignitethe impalpable dust. As malt-mills in breweries (for whichmy invention has especially been designed) are usually constructed andarranged, such explosive fires are not confined to the millbox ormill-room, but frequently extend through the pipes leading to theelevatorboot, which, being filled with inflammable dust, takes fire, andthe fire is carried on to the upper stories of the building, (beingaided by the upward draft caused by the motion of the elevator-cups) andthe entire structure frequently becomes a prey to the flames. It isbelieved that in a mill provided with my improvements such firescannot-become extensive, as, so to say,.they will be curbed or smotheredat birth.

I shall now proceed to describe in detail the construction, modusopcran'di, and the results E to the elevator.

of my invention, first, however, briefly ex-- plaining the usual generalconstruction of one type of malt-mill, all others known to me being, sofar as my present improvements have relation thereto, substantially thesame.

In the drawings, A marks the mill-room,

and'M the.mill-box therein; R R, the crushing-rolls, geared to rotate atdifferent speeds; I, the influx-pipe fromwhich the malt m descendsbetween said rolls, and E is the effluxpipe leading to the elevatorboot. (Not shown.)

I In the particular style of mill which I have selected forillustration, and which ismuch in vogue abroad, the inflow of the maltto the crushing-rolls is regulated by means of a gate or gage, acrossthe delivcry-pipe I, and which is vertically adjustable by means of athumb-nut, (Z, on the rod 6, extending above the pipe. The comparativelysmall stream of malt which has passed beneath the gage falls upon acurved faced block, I), termed the receiving-block, whence it is feddown in a thin-spread stream to the rolls R by a rotating feed-roller,c.

- Imay also state, although forming no p of my invention, that on itsway down the in flux-pipe the malt passes over a'plate-magnet, 2, whicharrests particles of iron which may have gotten into the malt, and alsothat the latter slides over a screen, 8, which extracts. a large part ofthe dust not taken out by previous screening, which dust falls into adust-chamber, D,'that may be emptied from time to time by removing thedoor or bottom a. The crushed malt, falling from between the rolls R, isconducted by the inclined pipe Now, the mill-box, as is well known, iscontinually filled during the crushing or grinding process with theflying very inflammable and dangerously explosive malt-dust, liable totake fire and explode at slight provocation, which is given the instanta spark isv thrown off by the rapidly-revolving rolls'striking a foreignhard body, such as a nail, stone, or a piece of self-binder wire, &c.The consequences of such an explosion are obvious and well known. Itmust find vent in some direction, and the readiest is by way of theexit-pipe E and the elevator, with the final results I have abovementioned. I prevent these by providing means, first, for keeping acontinuous eiiective barrier between the mill-box and the elevator-boot;second, iorinsuring a sufficient vent for the force of the explosionfrom the mill-box to the open air 5 and, third, for closing by devicesput into operation by and at the instant of the explosion within themill-box.

The barrier which I make use of to cut off the escape of the explosivegases and iire by way of the efiiux-pipe E is composed of and built upby the crushed malt itself.

It will be observed that the bottom part of the mill-box is contractedor hopper-shaped, and that there is a plenum of the malt m in thishopper and in the efliux-pipe adjacent thereto. This condition ismaintained at all times by means of the devices hereinafter described.Should an explosion now occur within themill-box, the gaseous pressureupon the top of the tapering body of malt tends to instantaneously packthe expanse of the latter into the contracted hopper and pipe, and thuscompel the volume of gases to find an easier vent. I preserve thisperpetual plenum by means of a device which I term a discharger,consisting of an adjustable gate or gage, G, and a feed-roller, O,placed in the pipe E a short distance below the mill-box, as shown.

This gage and roller are duplicates in eonstruction, arrangement,andoperation of those, 7 and c, in the in flux-pipe I,as before described.I do not, however, limitmyself to a discharger made precisely as shown,as any contrivance for accomplishing the identical purpose will bewithin the scope of my invention.

\Vhen the mill is first started up, the discharger is temporarilyadjusted, either by pushing down the gate G, so as to entirely close upthe pipe, or by checking the rotation of the roller 0, so as to causethe backing up of the malt until the pipe above and the hopper becomefilled, whereupon the discharger is regulated to allow the outflow ofthe maltmeal to equal the inilow ol' the malt, thereby preserving theestablished level of meal in the hopper.

I purpose applying a device for retarding or accelerating the actionofthe dischargcr, (or the i'ecder,) made to operate automatically by therelative quantity or height of the malt-meal within the pipe E and thehopper, and, perhaps, making the same the subject of future applicationfor Letters Patent.

The vent which I provide for the great volume of expansive gasessuddenly generated in case of the ignition ot' the malt-dust within themill-box, and which, as seen, are denied escape by way of pipe E,consists of an ample pipe, V, communicating with the interior of themill-box and with the free air outside the wall \V of the building.

An additional barrier between the mill-box and the elevator-boot, whichI provide as a further measure of safety when such an explosion occurs,consists of a gate, .I, in the efflux-pipe E, which normally is raisedor open, as in Figs. 1 and 8, but in case of explosion or fire is causedto descend and obstruct the passage-way of the eiiiux-pipe, as Ishallnow procecdto describe. This gate is connected by a rod, W, to adrop-lever, L, that is pivoted at one end, w, and its free end held upin the following manner: A rod or rope, X, to which the free end of thelever is fastened has aslotted block, Y, at the upper extremity, whichblock extends up through a slot in the under side of the vent-pipe V,which, it will be remembered, extends from within the mill-box. Thisblock, and by sequence the lever L, is held up by means of a wedge orkey, K, passed through a slotin the former, and bearing upon the bottomof the vent-pipe on either side of the slot therein, as clearly shown inFigs. 11. and i. I prefer to make this key of oiled wood or othermaterial that will not rust or stick, but which can always be reliedupon for the purpose in View. It is connected by means of a cord or red,2, with the cap Z, which covers the outer end of the vent-pipe. New,should an explosion take place within the mill-box, this cap will beblown off, thereby causing the withdrawal of the key K from the block,leaving the lever L free to drop by its gravity, and the gate J to bethereby carried down across and effectually close the eiiiuxpipe. Acatch or loop, 3, through which lever L is passed, serves to check itsfall, so as to avoid undue strain or breakage of the connections.

The positions of the several parts following an explosion arerepresented in Fig. 2 of the accompanying drawings, the cap Z beingblown off, the lever L fallen, and with it the gate J, across theciilux-pipe. The cap Z, besides serving the purpose hereinbeforementioned, at the same time keeps the vcnt-pipe closed at ordinarytimes, thus preventing the escape of the fine inflammable malt orgra-indust in that direction",

I prefer to make the connection, X, between the key K and the drop-leverof cotton, hemp, or other similar readily-inflammable material, which,burning, in case of fire occurring outside the mill-box, soon severs,and thereby allows the said lever to drop. This feature, however, Ishall make the subject of future application for Letters Patent. I alsoprefer to make the rope (or rod) X, instead of integral, in sections andconnect them, as seen in Fig. 5, with couplings U, composed of somefusible alloy which melts at a comparatively low degree of heat, andwhich, becoming melted from the heat in case of fire adjacent to theroom, breaks the connection between the said sections, and the leverfalls. This will also form the subject of an application for a patent,as will other devices shown and lettered inthe drawings, forextinguishing fires within and adjacent to the mill-box, and nothereinclaimed.

Having thus described my invention, I claim as new and desire to secureby Letters Iate11t 1. The method of preventing fires resulting fromexplosions of grain-dust within the millboxes of malt or other graincrushing or grinding mills from extending from the mill-box to l theelevatorboots and other parts of the building, which consists inmaintaining acontiuual plenum of the ground or crushed grain in theoutlet-pipe from the mill-boX, in conjunction with a suitable entleading from the latter into-the open air, substantially as set forth.

2. In combination with the mill-box having the grinding or crushingrolls therein and the .effluX-pipe leading therefrom, an adjustabledischarger for regulating the flow of the ground grain from theeffluX-pipe, so as to maintain the plenum in said pipe above thedischarger, substantially as and for the purposes set forth.

3. The mill-box having the grinding-rolls therein, and its bottomconical or hopper shaped, the effluX-pipe leading therefrom, and theadjustable discharger, all combined, constructed, arranged, andoperating substantially as and for the purposes described.

4. The combination, with the mill-box having the grinding-rolls therein,and the influx and eiflux pipes communicating therewith, a feeder in theformer pipe and a discharger in the latter, said feeder and dischargerbeing adaptedtoberelativelyadjusted and-regulated, so as to preserve acontinual plenum of the ground grain within the effluX-pipe,substantially as and for the purposes set forth.

5. The combination, with the mill-box having the grinding-rolls therein,and the influx and efflux pipes/of means for preserving the describedplenum within the efflux-pipe, and the vent-pipe V, communicating withthe interior of the mill-box, substantially as and for the purpose setforth.

6. In combination with the mill-box, effluxpipe, the gate J, and thedrop-lever L, connected with said gate, all constructed, combined, and

adapted to operate substantially as and for the purpose specified.

In testimony whereof I have hereunto affixed my signature this 24th dayof February, A. D. 1883.

CHARLES JOHN HEXAMER. Witnesses:

R1011. T. BOEHME, E. H.,ECKFELDT.

